#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <RTClib.h>

// Initialize components
LiquidCrystal_I2C lcd(0x27, 20, 4); // Change the address if needed
RTC_DS1307 rtc;
const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {1, 2, 3, 4}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 6, 7, 0}; //connect to the column pinouts of the keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

const int buttonPin1 = 9;
const int buttonPin2 = 10;
const int restartButtonPin = 8;

const int ledR = 13;
const int ledB = 11;
const int ledG = 12;

bool counting = false;
unsigned long startTime = 0;
unsigned long elapsedTime = 0;

enum EntryState {
  SHIFT,
  MACHINE,
  STOP_CODE,
  COUNTING
};

EntryState currentEntryState = SHIFT;
String enteredCode = ""; // Store entered code
bool restartPending = false; // Variable to track restart button press

void setup() {
  lcd.init();
  lcd.backlight(); // Turn on the backlight
  
  Wire.begin();
  rtc.begin();
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); // Set RTC to compile time

  pinMode(ledR, OUTPUT);
  pinMode(ledG, OUTPUT);
  pinMode(buttonPin1, INPUT_PULLUP);
  pinMode(buttonPin2, INPUT_PULLUP);
  pinMode(restartButtonPin, INPUT_PULLUP); // Set the restart button pin as input with internal pull-up resistor

  lcd.setCursor(0, 0);
  lcd.print("Enter the shift:");
}

void loop() {
  // Check for restart button press
  if (digitalRead(restartButtonPin) == LOW) {
    restartPending = true;
  }

  if (restartPending) {
    // Clear any previous data and reset variables
    enteredCode = "";
    currentEntryState = SHIFT;
    counting = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter the shift:");
    restartPending = false; // Reset the restart flag
  }

  char key = keypad.getKey();
  
  if (key && !counting) {
    if (currentEntryState == SHIFT || currentEntryState == MACHINE || currentEntryState == STOP_CODE) {
      if (key == '#') {
        if (enteredCode.length() > 0) {
          // Transition to the next entry state
          switch (currentEntryState) {
            case SHIFT:
              currentEntryState = MACHINE;
              break;
            case MACHINE:
              currentEntryState = STOP_CODE;
              break;
            case STOP_CODE:
              currentEntryState = COUNTING;
              lcd.clear();
              lcd.setCursor(0, 0);
              lcd.print("Press # to start");
              break;
          }

          lcd.clear();
          lcd.setCursor(0, 0);
          lcd.print("Enter ");
          switch (currentEntryState) {
            case MACHINE:
              lcd.print("Machine :");
              break;
            case STOP_CODE:
              lcd.print("Stop code :");
              break;
          }
          
          enteredCode = ""; // Clear entered code for the next entry
        }
         
       }  
        else if (key == '*') { // Check if "*" key is pressed
        enteredCode = ""; // Clear entered code
        lcd.setCursor(6, 1);
        lcd.print("        "); // Clear the display for entered code
      }
      
        else {
        enteredCode += key;
        lcd.setCursor(6, 1);
        lcd.print(enteredCode);
      }
    }
  }
  
  if (currentEntryState == COUNTING) {
    if (digitalRead(buttonPin1) == LOW) {
      if (!counting) {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Counting...");
        counting = true;
        digitalWrite(ledG, LOW);
        digitalWrite(ledR, HIGH);
        startTime = millis();
        elapsedTime = 0; // Reset elapsed time
      }
    }
  
    if (counting) {
      elapsedTime = millis() - startTime;
      lcd.setCursor(0, 1);
      lcd.print("Time: ");
      lcd.print(elapsedTime / 60000); // Display time in minutes
      lcd.print(" min ");
      lcd.print((elapsedTime / 1000) % 60); // Display time in seconds
      lcd.print(" sec");
    }
  
    if (digitalRead(buttonPin2) == LOW) {
      if (counting) {
        counting = false;
        digitalWrite(ledR, LOW);
        digitalWrite(ledG, HIGH);
        rtc.adjust(DateTime(F(__DATE__), F(__TIME__)).unixtime() + (elapsedTime / 1000)); // Set RTC to current time + elapsed time
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Count stopped");
        
        lcd.setCursor(0, 1);
        lcd.print("Downtime: ");
        lcd.setCursor(3, 2);
        lcd.print(elapsedTime / 60000); // Display time in minutes
        lcd.print(" min ");
        lcd.print((elapsedTime / 1000) % 60); // Display time in seconds
        lcd.print(" sec ");
  
        DateTime now = rtc.now();
        lcd.setCursor(0, 3);
        lcd.print("Date: ");
        lcd.print(now.year(), DEC);
        lcd.print("/");
        lcd.print(now.month(), DEC);
        lcd.print("/");
        lcd.print(now.day(), DEC);

    

      }
    }
  }
}